Q fever: persistence of antigenic non-viable cell residues of Coxiella burnetii in the host?implications for post Q fever infection fatigue syndrome and other chronic sequelae
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http://qjmed.oxfordjournals.org/cgi/content/full/102/10/673
<nobr>B.P. Marmion<sup>1</sup></nobr>, <nobr>O. Sukocheva<sup>2</sup></nobr>, <nobr>P.A. Storm<sup>1</sup></nobr>, <nobr>M. Lockhart<sup>2</sup></nobr>, <nobr>M. Turra<sup>1</sup></nobr>, <nobr>T. Kok<sup>1</sup></nobr>, <nobr>J. Ayres<sup>3</sup></nobr>, <nobr>H. Routledge<sup>3</sup></nobr> and <nobr>S. Graves<sup>2</sup></nobr> From the <sup>1</sup>Q fever Research Group, SA Pathology/Hanson Institute, Adelaide, South Australia, <sup>2</sup>Australian Rickettsial Reference Laboratory, Geelong, Victoria, Australia and <sup>3</sup>Environmental and Occupational Medicine, University of Birmingham, Birmingham, UK <sup> </sup>
Address correspondence to B. P. Marmion, Q fever Research Group, SA Pathology/Hanson Institute, Adelaide, Australia. email: bpmarmion@iprimus.com.au
Background: Our previous studies of persistence of Coxiella<sup> </sup>burnetii in humans after an initial acute Q fever infection<sup> </sup>revealed raised, maintained antibody levels and low levels of<sup> </sup>coxiella genomic DNA at the age of 5 years from onset in Australian<sup> </sup>patients and at 12 years in patients in the 1989 Birmingham<sup> </sup>UK Q fever outbreak. Attempts to isolate the coxiella in standard<sup> </sup>cell culture and susceptible mice by serial passage of PCR positive<sup> </sup>PBMC and bone marrow were negative.<sup> </sup> Aim: To retest PCR positive patient samples by more sensitive<sup> </sup>methods for viable coxiellas and for the coxiella cell components<sup> </sup>of antigen and specific lipopolysaccharide (LPS). To re-interpret<sup> </sup>the previous results in the light of the new information. To<sup> </sup>review the pertinent literature for a concept of an immuno-modulatory<sup> </sup>complex generated by the current studies.<sup> </sup>
Design: Laboratory case study.<sup> </sup>
Methods: Stored patient samples were inoculated into SCID mice<sup> </sup>that were followed for 60 days. Mouse spleen and liver samples<sup> </sup>were then examined by PCR assay for targets in the COM1 and<sup> </sup>IS1111a sequences and for antigens by IFA with a polyclonal<sup> </sup>rabbit antiserum to C. burnetii Phase 1 and a monoclonal antiserum<sup> </sup>to Phase 1 LPS (details; O. Sukocheva et al., unpublished data).<sup> </sup>
Results: All specimens, including a recently excised heart valve<sup> </sup>from a Birmingham patient with late developing endocarditis,<sup> </sup>were infection negative in SCID mice. Dilutions of SCID mouse<sup> </sup>spleen and liver homogenates titrated in PCR assays were negative<sup> </sup>at dilutions attained by control mice inoculated with an endpoint<sup> </sup>dilution of a viable prototype strain of C. burnetii. Sections<sup> </sup>of the spleens from all specimens showed a complex of coxiella<sup> </sup>antigen-LPS by IFA.<sup> </sup>
Discussion/Review: We advance a concept of long-term persistence<sup> </sup>of a non-infective, non-biodegraded complex of coxiella cell<sup> </sup>components with its antigens and specific LPS [so called Immunomodulatory<sup> </sup>complex (IMC)] associated with traces of genomic DNA that signalled<sup> </sup>its presence in our earlier studies. The IMC's survival in patients<sup> </sup>for at least 12 years, and in one patient for 70 years implies<sup> </sup>a capacity for serial passage in macrophages with effective<sup> </sup>down-regulation of their biodegrading functions. The review<sup> </sup>assesses the compatibility of the IMC concept in relation to<sup> </sup>cogent literature on C. burnetii interactions with macrophage<sup> </sup>and cell-mediated immunity. Some remaining gaps in our knowledge<sup> </sup>of the organ sites and duration of carriage of viable coxiellas<sup> </sup>after initial infection are also identified.
anne :
Q fever : the bacteria infects the macrophage.
60% asymptomatic
40 % flu illness ... in them 4% must be hospitalized ( some complications like endocarditis, hepatitis .. )
if chronical endocarditis : antibiotic treatment can last 3 years
in 10 or 15% Q fever give a " fatigue syndrome".
here you can find some articles :tiphat:
Jeannette found most or them
http://www.influenzah5n1.fr/index.php?topic=12530.0
http://www.influenzah5n1.fr/index.php?topic=11135.240
http://www.influenzah5n1.fr/index.php?topic=12597.msg44704;topicseen#new